It is one thing to fire your own wood kiln so many times that you know its behaviour. And, yes, we can predict certain things but students brand ‘new’ to wood firing or only having participated in a single wood firing workshop are handicapped to say the least. Our kiln was designed to use Poplar logs but we cannot get Poplar logs in the late fall. They have been cut and split for firewood sales. So, we tried oak slabs, very hard oak slabs and a partial grate. What did we discover? The kiln can reach 13.5 on the Oxyprobe in 12 hours with a 3 hour gas pre-heat. The top of the kiln needs to be ignored. Oak by itself is not good. It creates immense amounts of ember but if you want to raise the temperature and finish the job, it had to be mixed with scrap lumber and pine. The ration was 1 part oak to whatever else we could lay our hands on. The pots, as anticipated, that were placed in the throat had amazing yohen effects. Kusakabe would love them! The students also learned many things about the glazes.
In the ceramics area we have big pails of ‘shop glazes’. I have no idea who started this practice and, at times, it is a hindrance, not a help. The students – because the tiles show the glazes by themselves and then mixed with one other studio glaze, cause a lot of dipping. Dipping without thought, dipping and getting the glaze too thick and when the work comes out fantastic the dipping often causes blank looks on the faces of the students! Of course they have been told to have a method of recording so that they know what they did and could replicate it. One of the best of these ‘dipping’ pieces was a tea bowl by Jiawei Dai. I wish I had a photo of it. She put temmoku underneath and Haystack Green on the upper half. It was fantastic. In fact, those old Sun dynasty glazes fired in the wood kilns of 9th and 10th century China are superb. The other glazes were the ash ones that we made out of the Poplar ash from the first firing. Those included a Nuka (gorgeous soft white), a red made with half ash and half low fire red clay, and an amber.
The bagwall question plagued us. In the end, we put it at the back and loaded the middle half of the kiln tight and put Kewen’s walls there so that we would, hopefully, keep the flames dancing about and the ash as well. It seems to have worked great!
We also had lots of ash…did someone say a 12 hour firing in a Bourry box doesn’t produce ash? It does! and almost all of the students got to experience what every wood firing potter in the world knows: grinding is a part of the process. They also learned about alumina hydrate and the difference between wadding made with it and without.
They were a great group, full of laughter, great at problem solving, and community minded. Everyone did their part. Even one of the students who had recent foot surgery showed up on the last day and found that while they couldn’t be outside in the cold, they could grind and clean shelves. Incredible. They are such a good group and the plan is to fire the kiln again in April when the weather has warmed up (or in May) outside of a class for fun and also for them to be able to undertake it with some assurances about the oak and the other scraps and pine – that it works!